In the past, 2-methyl-3-buten-2-ol (MBE) has been manufactured by first reacting acetylene and acetone and then selectively hydrogenating the resulting 2-methyl-3-butyn-2-ol. This process requires relatively expensive process equipment and raw materials and creates at least one mole of calcium waste (derived from the reaction of water and calcium carbide to give acetylene), per mole of MBE produced by the process. This large amount of waste material gives rise to disposal problems.
An alternative process for manufacturing MBE has been developed which overcomes the aforementioned disabilities in manufacturing MBE from acetylene. This process utilizes isoprene as the starting material and involves the process steps of hydrohalogenation and subsequent solvolysis. See A. J. Ultee, Sr., Rec. Trav. Chim., Volume 68, pages 483-484 (1949) and U.S. Pat. No. 2,382,031. This alternative process requires relatively inexpensive process equipment (e.g., only one reaction vessel being required), relatively inexpensive raw materials, and creates only 1/2 mole of waste CaCl.sub.2 per mole of MBE produced, thereby substantially reducing the disposal problem.
However, the savings realizable from utilizing isoprene rather than acetylene in manufacturing MBE have not been as great as were anticipated. One reason for this is that the yields of MBE from this process have not heretofore proven to be very great. By this process, MBE has heretofore been obtained from isoprene in yields of no greater than about 20 to 50%. The yield of the MBE by this process has been reduced due to the formation of side products such as 2-methyl-4-hydroxy-2-butene (prenol). There has been a need for an improved process for manufacturing MBE from isoprene in relatively high yields i.e., yields about 80% or better.